Diadectidae

Diadectids; Temporal range: Late Carboniferous – Late Permian, (possible Early Carboniferous occurrence)
	Skeleton of Diadectes sideropelicus in the American Museum of Natural History
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Diadectomorpha
Family:	†Diadectidae; Cope, 1880
Genera
	†Alveusdectes; †Ambedus?; †Desmatodon; †Diadectes; †Diasparactus; †Kuwavaatakdectes; †Orobates; †Phanerosaurus; †Stephanospondylus;

Diadectidae is an extinct family of early tetrapods that lived in what is now North America and Europe during the Late Carboniferous and Early Permian, and in Asia during the Late Permian. They were the first herbivorous tetrapods, and also the first fully terrestrial animals to attain large sizes. Footprints indicate that diadectids walked with an erect posture.

The best known and largest representative of the family is Diadectes, a heavily built animal that attained a maximum length of several metres. Several other genera and various fragmentary fossil remains are also known. Although well known genera like Diadectes first appear in the Late Pennsylvanian, fragmentary remains of possible diadectids are known from much earlier deposits, including a piece of lower jaw found in Mississippian strata from Tennessee.